Air conditioning unit



March 10, 1953 A W, ARNOLD 2,631,021

AIR CONDITIONING UNITi Filed June 20, 1949 2 SHEETS--SHEET l mmlfmn.

March 10, 1953 A. w. ARNOLD AIR CONDITIONING UNIT 2 SHEETS--SHEET FiledJune 20, 1949 ein,

Patented Mar. 10, 1953 AIR CONDITIONING UNIT Albert W. Arnold, BeverlyHills, Calif., assignor to Jabsco Pump Company, Burbank, Calif., a

copartnership Application June 20, 1949, Serial No. 100,221

11 Claims.

This invention relates generally to air conditioning units andparticularly to improvements in devices for introducing either cool,moist air or warm, dry air into a room or other living space, suchdevices being commonly known as evaporative coolers.

Air conditioning units of the type referred to above are usually locatedoutside a building and include a box-like casing having an inlet openingthrough which fresh air is drawn into the casing by means of a poweroperated fan or blower unit, the air then being discharged through anoutlet opening in the casing from which point the fresh air is directedinto the building or a room thereof for breathing purposes. Such aircirculating devices are usually equipped with means for moistening andcooling the air, this means consisting of a water-saturable pad which isdisposed in the inlet opening and adapted to be saturated by waterapplied thereto from a suitable source and at a rate commensurate withthe rate at which the water is taken up by the air and the cooling andmoistening effect necessary to provide comfort for the occupants of theroom. It is frequently desirable to operate such an air conditioningunit with dry pads, as when ventilation without cooling best suits theneeds of the occupants of the room or other compartment and in this casethe supply of water to the pads is diminished or entirely shut off.

In many evaporative coolers water is conveyed to the fibrous saturablepad from a water main in sufficient quantity to thoroughly wet the padand since muc-h of the Water drips oi from the lower edges of the pad,it is wasted through a drain pipe.

To operate such an air conditioning'k unit in a manner to merelyventilate the room without cooling the same, a hand valve in the watersupply line is closed.

Another type of evaporative cooler unit employs a motor driven pumpwhich draws water from a catch pan or reservoir located beneath the pad,the water being supplied to the reservoir from a water main and pumpedonto the pad, the surplus water falling back into the reservoir. Thesupply of water to the reservoir is controlled by a ioat valve in thereservoir, this valve operating to maintain a substantially constantquantity of water in the reservoir. The operation of the electric motorfor the pump is controlled from an electric switch disposed at aconvenient location. It is common to provide in air conditioning unitsof the type last discussed a pair of electric motors, one motor drivingthe fan or blower and. the other motor operating the pump.

Thus, the cost of the unit is high and operational control of the unitis complicated.

It is an object of my invention to obviate the disadvantages of previousair conditioning units of the evaporative cooler type by providing aunit of this character which is extremely simple in construction,economical to manufacture and operate, and which is highly efficient inperforming the function of supplying either cool, moist air or warmer,dry air to a room or other compartment.

Another object is to provide a unit of the type referred to whichutilizes a pump for pumping water from a reservoir within the casingonto a pad or pads, the pump being driven from theA motor operated fanor blower so that a single motor actuates all the operating parts, thisarrangement making for greater simplicity in construction and operation.

Another object is to provide a unit ofthe type indicated which employs aoat type valve for controlling the flow of water from a water main intothe reservoir so as to maintain a predetermined, substantially constantquantity of water in the reservoir, the water main or supply line havinga manually operable valve by which the iow of water therethrough can beselectively initiated or stopped when it is desired to furnish cool,moist air or warmer, dry air to the room or other compartment.

In previous air conditioning units of this general character closing ofthe valve in the water supply line merely stops the ow of water from theWater main into the reservoir. Consequently, unless the operation of thepump is promptly arrested, the pump continues to convey the water in thereservoir Lonto the moistening pads until all of the water has beentaken up by the air.

It is thus apparent that if the operator inadvertently fails to open theswitch of the pump motor circuit, the until will continue to moisten andcool the air until .such time as the water in the reservoir iscompletely dissipated and the desired change in the humidity andtemperature of the air is substantially delayed. It is another object ofthis invention to eliminate such an undesirable condition by providingcontrol means responsive to reduction in water pressure in the watersupply line, when the valve is closed, for inactivating the means forconveying the water from the reservoir to the saturable pads.Specically, this means is responsive to a reduction in pressure of .the

water in the supply line between the manual valve and the float actuatedvalve, below a predetermined value. By this provision, a slight loweringof the water level in the reservoir, following closing of the supplyline valve, causes reduction in water pressure and effects promptdiscontinuance of the feeding of water to the pads so that conversionfrom cool, moist air Ato warmer, dry air is produced without anyappreciable time lag.

In accordance with the invention, the object discussed immediately abovemay be best accomplished by either permitting the pump to remainoperative and automatically by-passing the water pumped thereby backinto the reservoir, or by discontinuing the operation of the pump byautomatically disconnecting the` pump from the motor-driven fan orblower.l In either arrangement, the conveying1 of the water from thereservoir to the pads is promptly arrested in response to a reduction inwater pressure in the supply line downstream from the manually operablevalve so that the change from cool, moist air to warmer, dry air iseffected by the simple act of closing said valve'.

A still further object is to provide pressure relief means associatedwith the water supply valve and operative automatically when the valveis closed to effect immediate reduction of pressure in the water supplypipe and, consequently, prompt inactivation of the pad wetting means.

Further objects of my invention will become apparent from the followingdescription and from the drawings, which are intended for the purpose ofillustration only, and in which:

Fig. 1 is a cross-sectional view through an air conditioning unitconstructed in accordance with one embodiment of my invention;

Fig. 2 is an enlarged detail of the float-actuated valve;

Fig. 3 is an enlarged detail of the pressure responsive valve;

Fig. 4 is a cross-sectional View through an air conditioning unit ofsomewhat modified construction;

Fig. 5 is an enlarged cross-sectional view, taken on` line 5-5 of Fig.4; and,

Figs. Gand 7 are diagrammatic views of an alternative water supply valveadapted for use in connection with the air conditioning units disclosedin Figs. 1 and 4'.

Referring to the drawings in detail, I illustrate in Figs. 1 to 3,. onepreferred embodiment of the invention, the air conditioning unit showntherein being, in eifect, an air duct and including a box-like housingID having a top wall II, side walls I2, and a bottom wall I3. which hasa central depressed portion providing a reservoir I4 adapted to containWater. Theends of the housing III are left open to provide air inlet'openings I5, and pads I6 of saturable brous material are disposed inthese openings so that air entering the housing must pass through thepads. An outlet opening Il is provided in at least one side Wall I2 ofthe housing through which the air can be discharged from the housing.Secured to the top wall II are trough elements I8 which are adapted tocontain water and over a side of which the water can flow down onto thesaturable pads I6, the troughs being connected by a water tube I9.

A blower casing 22 is supported by the bottom wall I3 of the housing I0,the casing having air inlet passages 23 in itsl end walls 24. Rotatablein bearing brackets 25 mounted on the end walls 24 is a blower shaft 2Swhich carries, within the casing, blade elements 2T of a fan or blowerV28. When the shaft 25 is rotated, the fan 28 functions to draw fresh airfrom the atmosphere through the pads I6, the air then passing throughopenings of the casing 22 and discharging through the outlet openingI'I, from which point the air may enter the room or other compartmentwhich is to be air conditioned. The blower unit 28 is driven from anelectric motor 30 mounted on the casing 22, the motor shaft carrying apulley 3I. which drives a larger pulley 32, fast on the blower shaft 26,through the medium of a belt 33.

Water is supplied to the reservoir I4 for moistening purposes through awater supply line 35 which may be connected to a water main, not shown,a manually operable valve 36 in the line 35 being provided for thepurpose of establishing flow of. water through the line into thereservoir I4 and shutting off the flow, as desired. The water supplyline 35 is connected to a T tting 31 having openings 38 and 39 disposedwithin the reservoir I4. Assuming for the present that the opening 39-is closed, water flowing upwardly through the supply line 35 dischargesthrough the opening 38 into the reservoir I4 and it is desirable tomaintain an adequate quantity ofthe water therein for air moisteningpurposes. In order to insure a substantially constant supply of water inthe reservoir, I prefer to employ a float-actuated valve, indicatedgenerally at 40 in Fig. 1 and shown in detail in Fig. 2. The valve 4i)consists of a float arm 4I which is pivoted at 42 on a suitable bracket43 and carries a float 44 at one end. At its other end, the oat arm 4Iis provided with a conical valve element 45 which is adapted to enterthe opening 38v of the T fitting 31' to regulate the rate of flow ofWater into the reservoir and to completely shut off the flow when thereservoir contains a predetermined quantity of the water.

It has been indicated that the water in the reservoir I4 is fed upwardlyinto the troughs I8 from which the water overflows onto the saturablepads I6. The feeding of the water to the troughs is effected by waterconveying means which is indicated generally at 49 in Fig. 1 andconstructed as next described. A pump 50 is ixedly disposed in thehousing I0 and its shaft 5I is axially aligned with and rotated by theblower shaft 26, a suitable coupling 52 connecting the shafts. Thus, thepump is driven continuously from the blower unit 23, as long as theblower unit remains operative. A suction pipe 53 connected to the inletof the pump 50 extends downwardly into the water within the reservoirI4, and a second pipe 54 connected to the discharge port of the pumpextends upwardly and is joined to the tube I9. It is apparent,therefore, that during operation of the pump 50, water is drawn upwardlyfrom the reservoir I4 and' delivered continuously to the troughs I8 soas to cause the pads I6 to be saturated to the degree necessary tomoisten and cool the air drawn through the pads and delivered to theroom being air conditioned.

As previously explained, it is frequently desirable to circulate air atatmospheric temperature and humidity through the room. In order todiscontinue the moistening of the air being forced into the room, thevalve 36 may be closed to stop the flow of water into the reservoir I4.It is obvious, however, that since the pump 53 operates continuously, itwill function to transfer water from the reservoir to the troughs I8until the supply in the reservoir is depleted. Consequently, even thoughthe water supply is hut off by the valve 36, the air delivered to theroom will continue to be moistened and cooled for a considerable periodof time and a quick change in the condition of the air within the :i

f Connected to the discharge pipe 54of the pump 56 is a by-pass line 55which extends downwardly with its lower open end disposed within thereservoir I4. The bypass line 55 comprises an upper section 56 and alower section 51, av

by-pass line 55 are connected to the upper cas-v ing section 6I andcommunicate with the chamber B5. A tube 68 has its upper end screwedinto the casing section 62 and is in fluid communication with the lowerchamber 66, the lower end of the tube being secured within the opening39 of the T fitting 31.

During normal operation of the air conditioning apparatus, that is, whenthe unit is operativeA to moisten and thus cool the air which itdelivers to a room or other compartment, the

valve 36 is open to admit water to the reservoir I4. At this time, thewater pressure within the upper end of the supply line 35 and the T-lfitting 31 also exists in the tube 58 and .this pressure is sufficientto flex the diaphragm 64 upwardly, as indicated by the broken lines inFig. 3, so as to close the upper end of the bypass line section 51.Consequently, all the water,v drawn upwardly fromv the reservoir I4 isdelivered 1 to the troughs I3 to effect wetting of the pads I 6. *I

When it is desired to introduce air of atmospheric temperature andhumidity into the room,l

or other compartment the air conditioning unit is operated with the padsI6 in a dry condition. To effect such a change in the character'of the'kY introduced air, it is merely necessary to close the water supply valve36 to stop the fiow of water. At this time water pres'- sure remains inthe line 35 downstream from the valve 36 and in the tube 68 so thattheby-pas's" line 55 is maintained closed by the pressure-j responsivediaphragm 64 and the pump 50;

into the reservoir I4.

which continues to operate, acts to draw a small quantity of waterupwardly from the reservoir.

This immediately causes the float arm 4I 'to pivot, thereby opening theneedle valve 38, 45 to relieve the water pressure so that the diaphragm64 fiexes downwardly to open the by-pass line 55.

Consequently, the water which is drawn from-Y the reservoir by the pumpreturns thereto by way of the by-pass line and thus is prevented-v fromfiowing to the troughs I8. Thus, the pads I6 are permitted to dry outand air which is thereafter drawn through them remains atl at'`"Jinospheric temperature and humidity and is merely cleaned by the drypads which act as lters for this purpose.

When it is again desired to cool the air flowing into the room, thevalve 36 is opened to introduce water into the reservoir through the4needle valve 38, 45 and as the level of the Water rises, the float 44acts to at least partially close the needle valve, thereby creatingwater pressure in the fitting 31 'and line 68. This condition results inthe exing of the diaphragm 64 upwardly so that the by-pass line 55 isclosed and all water drawn upwardly bythe pump 50 is delivered to thetroughs I8 for saturating the pads I6.

Referring now -to Figs. 4 and 5, my invention further contemplates acontrol means 10 which is particularly adapted for use in connectionwith an air conditioning unit having a pump 1I, the operation of whichis stopped when it is desired to operate the unit with dry pads. Thealternative control means is shown in connection with a. housing,blower, motor, etc., which are identical with the correspondingcomponents shown in Fig. land therefore designated by the same referencenumerals. The pump 1I is supported by and arranged to slide verticallyon a guide bracket 12 mounted in the housing I0, the pump being providedwith studs 13 which slide in a slot 14 of the bracket (Fig. 5).

In this embodiment of the invention, the pump shaft is offset downwardlyfrom the blower shaft 26 but is driven therefrom by means of pulleys 15and 16 on the respective blower and pump shaft-s, and a belt 11encircling the pulleys. By moving the pump 1I downwardly and upwardly,the belt 11 is respectively tightened and loosened to selectively renderthe pump operative or inoperative. When the pump is driven, it acts todraw water upwardly from the reservoir I4 through a suction pipe 19 vandto pump the water upwardly through a discharge pipe 8G and connectingline I9 into the troughs I8, the pipe 88 having a fiexible section 8|.

Means is provided for automatically shifting the pump 1I in eitherdirection, this means being pressure responsive and including a cylinderelement fixed within the housing I0. A piston 88 is slidable in thecylinder element 85 and has a rod extension 81 which is connected to thehousing of the pump 1 I.

A coil spring 88, disposed in the cylinder element 85, engages the lowerside of the piston 66 and thus normally tends to force the piston 85andpump 1I upwardly so as to loosen the drive belt 11 suiiiciently todisrupt the operation of vthe pump so that no water will be supplied tothe pads I6. However, the upper end of the cylinder is maintained iniiuid communication with the T fitting 31 by means of a pipe 98 so thatwhen the valve 36 is open, as when it is desired to maintain the pads I6wet to supply cool, moist air to the room, water pressure obtaining inthe T fitting 31 is also applied against the upper end of the piston 86to force the latter downwardly against the action of the spring 88.

It is thus seen that as long as the valve 36 remains open and water issupplied to the reservoir I4, the pump is maintained operative bydrawing the pump downwardly to tighten the belt 11, the fiexible portionBI of the pipe 86 permitting such movement of the pump. When it isdesired to discontinue the injection of cool, moist air into the roomand to supply air of atmospheric temperature and humidity, the watersupplyvalve 36 is closed. While sufficient pressure may exist at thistime in the tting 31 to maintain the pump 1I operative, this pressure isvery soon dissipated due to the fact that the fioatactuated valve 40opens. When the pressure within the cylinder element 85 is thusrelieved, the spring 88 forces the pump 1I upwardly to loosen the belt11 and disrupt the drive. Thus.' the control means 13 operatesin'respo'nse to :duid pressure in the fitting 31, when the Valve 36 isopen, to energize the pump 1I so asl to wet the pads I, and functions inresponse to-a reduction in pressure in the fitting below a predeterminedvalue, as governed by the strength of the spring 8 3, to inactivate thepump to discontinue the wetting of the pads. The control means 18 is incommunication with the T tting 31 by means of a pipe St so that when thevalve 38 is open, as when it is desired to maintain the pads l5 wet tosupply cool, moist air to the room, water pressure obtaining in the Tfitting 31 is also applied against the upper endof the piston 86 toforce the latter downwardly against the action of the spring 88.

It is thus seen that as long as the valve 36 remains open and water issupplied to the reservoir i4, the pump remains in lowermost position totighten the belt 11, the iexible portion 8! of the pipe 3S permittingsuch movement of the pump. When it is desired to discontinue theinjection of cool, moist air into the room and to supply air ofatmosphericV temperature and humidity, the water supply valve 36isclosed. While suilicient pressure may existat this time in the fitting3'! to maintain the pump 1l operative, this pressure is very soondissipated due to the fact that the neat-actuated valve 40 opens toadmit water from the T iitting into the reservoir It. When the pressureWithin the cylinder element 85 is thus relieved, the spring S8 forcesthe pump 1i upwardly to loosen the belt 'il'v and disrupt the drive.Thus, the control means `1t operates in response to fluid pressure inthe vfitting 31, when the valve 3G is open, toenergize the pump 1| so asto wet the pads I6, and functions in response to a. reduction inpressure in the liitting below a predetermined value, as governed by thestrength of the spring S3, to inactivate the pump todiscontinue thewetting of 'the pads. `The control means 19 is highly sensitive andemcient and by its use the air being introduced into a room or othercompartment can be selectively made cool and moist or warmer andrelatively dry bylthe simple act of opening and closing the Water supplyvalve 3G. It has also been shown that the air conditioning unit isfurther simpliiied in construction and operation by driving both theblower unit and the pump from va single electric motor so that it isunnecessary to inactivate the pump by shutting oii a separate drivingmotor therefor, as is the case in conventional air conditioning unitsutilizing water pumps.

Referring now to Figs. 6 and 1, it is within the concept of thisinvention to providevalve means Q5 for further expediting the reductionin'pressure in the T tting 31 and lines 68=and`9ll so as to promptlyrender the pad 4wetting lmeans ineffective. The valve means 95 replacesthe shuton" valve 3s shown in Figs. 1 ande and is a threeway valvehaving a casing 96 provided with a bleed port 91, the casing also havinga transverse port 88 through which water can flow into the T iitting 31.A valve member 95 rotatable in the casing 9S has a T-shaped passagetherein providing a straight transverse port I9@ and a branch port mi.When the valve member 99 is in the position shown in Fig. 6, 'water mayflow upwardly through the T iitting 31 into the reservoir i4 and, aspreviously explained, the pressure of the water in the T fitting and inthe lines 68 or 90, as the case may be, to maintain the pad wettingmeans operative. However, when the valve member 53 is rotated totheposition illustrated in- Fig. 7, the ow-of water to the 'reservoir I4is shut off and pressure of the water in the upper portion of the pipe35 and in the lines 68 or 90 is immediately relieved due to the factthat the water in these lines may bleed through the port 91. It is thusseen that when the valve means S5 is operated to shut on? the supply ofwater to the reservoir, water pressure in the unit is immediatelyreduced to zero so that inactivation of the pad wetting means ispromptly eected and the conversion from cool, moist air to drier air ofatmospheric temperature is greatly expedited. f While Amy improved airconditioning unit has been herein disclosed as embodied in severalpreferred forms of construction, by way of example, it will be apparentto one skilled in the art that various modifications might be made inthe structure without departing from the spirit of the invention.Consequently, I do not wish to be limited in this respect, but desire tobe aorded the full scope of the appended claims.

I claim as my invention:

l.. An evaporative cooler, comprising: a housing having inlet and outletopenings therein and Walls defining a reservoir for containing water;power operated fan means for drawing air through said inlet opening intosaid housing and discharging the same through said outlet opening; watersaturable material in said inlet opening through which the air passes; aconduit through which the water can flow from said reservoir to saidmaterial to saturate the same; a pump for eiecting flow of water throughsaid conduit; a by-pass line connected to said conduit downstream fromsaid pump and adapted to return water from said pump to said reservoir;a pressure water line for supplying water to said reservoir; a manuallyoperable valve in said Water supply line; and a pressureresponsive valveconnected in said by-pass line and operatively connected to said watersupply line, said pressure-responsive valve being normally maintainedclosed in response to pressure of predetermined value in said watersupply line so as to prevent return flow of Water from said conduit tosaid reservoir, but adapted to open in response to a reduction inpressure in said supply line below said predetermined value, when saidmanually operable valve is closed, to allow such return flow` 2. Anevaporative cooler as defined in claim 1, including a float-operatedvalve for controlling the iiow of water from said supply line into saidreservoir, the closing of said manually operable valve and the openingof said float-controlled valve causing the reduction in water pressurein said supply line to actuate said pressure-responsive valve.

3. An evaporative cooler as dened in claim 1 in which saidpressure-responsive valve includes a housing, a flexible diaphragmwithin said housing and dividing the interior thereof into a rst chamberand a second chamber. said rst chamber being in iiuid communication withsaid con-v duit and said reservoir, and said second chamber being iniiuid communication with said water supply line downstream from saidmanually operable valve. fluid pressure in said supply line and saidsecond chamber causing flexing of said diaphragm in one direction toclose said first chamber so as to prevent return iiow of water from saidconduit to said reservoir, and reduction in said pressure allowingflexing of said diaphragm in the opposite direction so as to open saidrst chamber to allow return ow of the Water to said reservoir.

4. An evaporative cooler as dened in claim 1 in which said poweroperated fan means drives said pump.

5. An evaporative cooler, comprising: a housing having inlet and outletopenings therein and walls defining a reservoir for containing` water;power operated fan means for drawing air through said inlet opening intosaid housing and discharging the same through said outlet opening; watersaturable material in said inlet opening through which the air passes; apressure water line for supplying water to said reservoir; a manuallyoperable valve in said water line; a conduit through which the water caniiow from said reservoir to said material to saturate the same; a pumpmovably mounted in said housing for effecting iiow of water through saidconduit, said pump being drivingly connected to said power operated fanmeans when moved in one direction and disconnected therefrom when movedin the opposite direction; and moving means responsive to water pressureof predetermined value in said supply line for moving said pump in saidone direction and to a reduction in said water pressure below saidpredetermined value for moving said pump in said opposite direction.

6. An evaporative cooler as defined in claim 5 in which said fan meanshas a rotary shaft and in which said pump has a rotary shaft and ismovable toward and away from said fan shaft, and including a pulley onsaid fan shaft; a pulley on said pump shaft, and a belt surrounding saidpulleys by which said pump can be driven, movement of said pump in adirection away from said fan shaft tightening said belt to effect saiddrive, and movement of said pump toward said fan shaft loosening saidbelt to distrupt said drive.

7. An evaporative cooler as defined in claim 5 in which said movingmeans includes a stationary cylinder; a piston slidable in said cylinderand operatively connected to said pump, one end of said cylinder beingin fluid communication with said water supply line downstream from saidmanually operable valve so that one side of said piston is exposed tosaid water pressure of predetermined value to be forced thereby in a rstdirection to eect movement of said pump in said one direction; and aspring disposed within the other end of said cylinder and engagingagainst the other side of said piston, said spring being operative tomove said pump in said opposite direction upon reduction of said waterpressure below said predetermined value.

8. An evaporative cooler as defined in claim 5 in which said movingmeans includes a stationary cylinder; a piston slidable in said cylinderand operatively connected to said pump, one end of said cylinder beingin fluid communication with said water supply line downstream from saidmanually operable valve so that one side of said piston is exposed tosaid water pressure of predetermined value to be forced thereby in a rstdirection to effect movement of said pump in said one direction; and aspring in said cylinder engaging the other side of said piston andoperative to force the same in the opposite direction upon reduction ofsaid water pressure below said predetermined value.

9. An evaporative cooler, comprising: a housing having inlet and outletopenings therein and walls defining a reservoir for containing water;power operated fan means for drawing air through said inlet opening intosaid housing and discharging the same through said outlet opening; watersaturable material in said inlet opening through which the air passes;flow inducing means normally operative to effect flow of Water from saidreservoir to said material to saturate the same; a pressure water linefor supplying Water to said reservoir; a manually operable valve in saidwater line for controlling the flow of water therethrough; afloat-operated valve for controlling the delivery of Water from saidline into said reservoir so as to maintain a substantially constantvolume of water in said reservoir; control means responsive to reductionin pressure in said water line below a predetermined value, when saidmanually operable valve is closed, for rendering said Iiow inducingmeans ineifectual; and pressure relief means operative automatically inresponse to closing of said manually operable valve to relieve the waterpressure in said water line.

10. An evaporative cooler as defined in claim 9 in which said pressurerelief means is incorporated in said manually operable valve.

11. An evaporative cooler as defined in claim 9 in which said manuallyoperable valve is of a three-way type, said pressure relief meansincluding a bleed port in said valve.

ALBERT W. ARNOLD.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STATES PATENTS Number Name Date 1,792,590 Kirk Feb. 17, 19311,870,196 Hegan Aug. 2, 1932 1,965,866 Tolman July 10, 1934 2,156,317Smith et al May 2, 1939 2,201,647 Feinberg May 21, 1940 2,235,116 RayMar. 18, 1941 2,237,497 Munford Apr. 8, 1941 2,242,186 Stair May 13,1941 2,539,344 Carraway Jan. 23, 1951

